A systematic review and meta-analysis of adolescent nutrition in Ethiopia: Transforming adolescent lives through nutrition (TALENT) initiative

Background Ethiopia has undergone rapid economic growth over the last two decades that could influence the diets and nutrition of young people. This work systematically reviewed primary studies on adolescent nutrition from Ethiopia, to inform future interventions to guide policies and programs for this age group. Method A systematic search of electronic databases for published studies on the prevalence of and interventions for adolescent malnutrition in Ethiopia in the English language since the year 2000 was performed using a three-step search strategy. The results were checked for quality using the Joanna Bridge Institute (JBI) checklist, and synthesized and presented as a narrative description. Results Seventy six articles and two national surveys were reviewed. These documented nutritional status in terms of anthropometry, micronutrient status, dietary diversity, food-insecurity, and eating habits. In the meta-analysis the pooled prevalence of stunting, thinness and overweight/obesity was 22.4% (95% CI: 18.9, 25.9), 17.7% (95% CI: 14.6, 20.8) and 10.6% (7.9, 13.3), respectively. The prevalence of undernutrition ranged from 4% to 54% for stunting and from 5% to 29% for thinness. Overweight/obesity ranged from 1% to 17%. Prevalence of stunting and thinness were higher in boys and rural adolescents, whereas overweight/obesity was higher in girls and urban adolescents. The prevalence of anemia ranged from 9% to 33%. Approximately 40%-52% of adolescents have iodine deficiency and associated risk of goiter. Frequent micronutrient deficiencies are vitamin D (42%), zinc (38%), folate (15%), and vitamin A (6.3%). Conclusions The adolescent population in Ethiopia is facing multiple micronutrient deficiencies and a double-burden of malnutrition, although undernutrition is predominant. The magnitude of nutritional problems varies by gender and setting. Context-relevant interventions are required to effectively improve the nutrition and health of adolescents in Ethiopia.

original research from Ethiopia, thereby collating current evidence on nutritional status of Ethiopian adolescents and the effectiveness of nutritional interventions in this age group.

Search strategy
We adopted a rigorous systematic approach [16,17]. The first step was to formulate objectives/research questions as follows.
1. From observational studies and surveys, what is known about the nutritional status of Ethiopian adolescents (boys and girls age 10-19 years) in terms of: a) body size and energy balance (chiefly weight, BMI and height), b) micronutrient status, c) dietary intake, diversity and quality, and d) dietary behaviours?
2. From their associations with population characteristics, what is known about the possible determinants of these aspects of nutritional status? Which adolescents are at risk of nutritional problems?

From intervention studies, what is known about the effectiveness of nutritional interventions in the Ethiopian population?
A three-step comprehensive literature search strategy was used to locate relevant literature published over the last 20 years from Ethiopia. Firstly, we set relevant key words and terms, using a logic grid for each key term. The terms used included "nutrition", "micronutrient", "malnutrition", "undernutrition", stunting", "thin", "obesity", "food insecurity" "dietary diversity" "anemia", "iron", "folic", "vitamin", "zinc", "iodine", "copper", "magnesium", "selenium" and "eating disorder". The terms we used to define the population were "adolescent", "teenage", "youth", "school children" and "young child", and setting in "Ethiopia".

Data sources/base
The search query was first developed for PubMed and later extended to EBSCO/ERIC and EBSCO/CINAHL to identify different concepts in the literature. Secondly, we carried out the search, expanding all terms in specific databases. Thirdly, we manually searched the reference lists of the identified studies.

Study selection process
Following the search, two researchers (AW & DH) screened studies by title. Then two independent researchers (BZ & RA) screened the abstracts and assessed the eligibility for full text retrieval. Selected full-text studies were compared between the reviewers, with disagreements being resolved through discussion and consensus with a 3 rd researcher (MA).

Findings of the review
Nutritional status defined by anthropometry, and its determinants. Forty studies, on a sample of 25 397 adolescents, and one demographic and health survey (DHS) [75] addressed nutritional status as defined by height, weight and BMI. Five specifically assessed over-
From studies that reported Z-scores for adolescents' height-for-age (HAZ) and body-massindex (BMI)-for-age (BAZ) using the 2007 WHO growth reference, the minimum and maximum mean HAZ was -1.5 [33] and -0.5 [41] while they were -1.29 [33] and 0.44 [89] for BAZ respectively. A comparison between urban and rural adolescents showed that the mean BAZ and HAZ were significantly higher in urban than rural adolescents, with mean differences of 0.2 (95% confidence interval (CI): 0.02-0.34) and 0.58 (95% CI 0.45-0.72), respectively [32]. Both HAZ and BAZ, even for urban adolescents were, however, lower than the WHO reference data [32].
Nutritional status trends over time. We searched for individual articles published since 2000, but data on the nutritional status of adolescents was only available between 2010 and 2022 The data from individual studies showed no clear pattern across time (Figs 2-8); and both undernutrition and overnutrition have co-existed over the last 10 years. A high prevalence of stunting (54% and 51%) was documented in 2014 and 2018, respectively; while a prevalence of 80.8% underweight and 44% thinness was documented in 2015. Likewise, the highest prevalence of overweight (17%) was documented in 2018.
Predictors of nutritional status. In ten of thirteen studies, adolescents from rural areas were more likely to be stunted compared to urban adolescents [22,30,32,33,39,41,51,59,62,64]. The prevalence of thinness was higher among adolescents from less educated mothers, adolescents who have <3 meals per day and those from households comprising more than five people. In addition, adolescents who were physically inactive and adolescents with sedentary lifestyles were more likely to be obese than others [44].
The reviewed articles [22,30,32,33,39,41,51,59,62,64] also identified common predictors for under-as well as overnutrition. Low dietary diversity, low frequency of daily food intake, higher household family size, low maternal education, food insecurity, and poor quality sources of drinking water were associated with undernutrition. In contrast, residency in urban settings, female sex, low levels of physical activity and a more sedentary life style are predictors of overweight/obesity (Table 1).
The national prevalence of anaemia by sex and setting was similar (20.4%) for rural girls and boys while it was 16.7% for girls and 8.6% for boys in urban settings. The national trends in anemia prevalence in girls aged 15- [75].
Three studies reported mean DDS scores below the average recommended value; 3.3 in southwest Ethiopia [80], 3.5 in northern Ethiopia [83], and 4.3 in Jimma Town [85]. Only one study from an urban setting in south western Ethiopia (Jimma town) reported mean DDS above average (6.97) and cereal based (99.6%) and vegetables (73.9%) diet were the two commonly consumed food types. However, this study did not report the prevalence of low/high DDS [44].  In terms of site preference for nutrition interventions, as reported by adolescents, schools (45%), health centers (27%) and health posts (26%) were the preferred public facilities for provision of iron supplements to school adolescents, while schools (11%), health centers (47%) and health posts (41%) were the preferred public facilities for provision of iron supplements to out-of-school adolescents [83]. In the same study, it was indicated that a lack of nutrition messages specifically for young people, low community awareness about adolescent nutrition, religious and cultural influences, perceiving iron as a contraceptive than a nutrition product, and lack of confidence in the supplementation value of iron tablets are barriers to the uptake of adolescent nutrition interventions in northern Ethiopia (Table 3).
Food insecurity. Seven studies [23-27, 46, 86] with a sample size of 10 866 adolescents assessed food insecurity, of which five came from the Jimma Longitudinal Family Survey of Youth (JLFSY) study [23][24][25][26][27] which followed 2 084 adolescents over three years. The remaining two studies were cross sectional surveys with a sample size of 784 adolescents in areas producing Khat (a common evergreen plant in eastern Africa used for its psychoactive properties) and coffee. Food insecurity was assessed using the adolescent food insecurity assessment scale adopted from household food security questionnaire [107], which enquires about their experience or concern about access to food or money.

Settings Sample Age Sex Exposure (s) Outcomes (s) Main findings
Getaneh Z, 2017 [68] To assess the prevalence and associated factors of anemia  adolescents were food insecure during each consecutive round of the survey respectively [27].

Discussion
In this review, it was possible to extract, synthesize and summarize considerable data on nutritional status and associated factors, food insecurity, dietary diversity, micronutrient status, and disordered eating from studies among adolescents in Ethiopia. The review generally showed that there is more undernutrition (stunting, thinness and micronutrient deficiencies) than overweight among adolescents. The prevalence of thinness and stunting is higher among boys and rural adolescents whereas overweight and obesity are higher among girls and urban adolescents. The review also revealed that adolescent food insecurity and low dietary diversity are common. Consequently, a large proportion of adolescents have one or more micronutrient deficiencies. About 80% and 60% of adolescents from rural and urban settings respectively were found to have low dietary diversity. Our review supports a report from WHO [108] which documented that the magnitude of undernutrition, micronutrient deficiency, overnutrition, inadequate or unhealthy diet and life styles is high among adolescents in LMICs.
The finding from the current review showed that the magnitude of undernutrition and low DDS is substantial. Although the prevalence of overweight is low compared to that of undernutrition, it appears that problems of overnutrition are emerging before Ethiopia has dealt with the burden of under-nutrition. This is in line with global data which shows that a double burden of malnutrition is increasing in LMICs [109] as they experience rapid economic growth, urbanization, and changes in dietary habits and levels of physical activity. Undernutrition (underweight, stunting and thinness) is more prevalent in younger adolescents, boys, and rural adolescents, whereas overnutrition (overweight and obesity) is higher in females and urban adolescents. Adolescents in rural settings are more likely to be engaged in various labour intensive (energy consuming) domestic activities to support their family. In addition, household food insecurity is higher in rural compared to urban communities because of low literacy rates, recurrent droughts, and lack of diversity in sources of income. In contrast, because of urbanization and concomitant changes in lifestyle, urban adolescents are more likely to consume low quality foods such as sweets and fast foods, have more screen time and spend more time sedentary. There are more limited opportunities for physical activity in urban environments, especially for girls, because of overcrowding and lack of space. In a recent qualitative study, we identified that boys have more opportunity for leisure time and outdoor physical activity than girls [110].
Geographically, undernutrition is higher in northern compared to southern Ethiopia. The community in the north Ethiopia is characterized by subsistence farming where crops are the main source of income, there is greater food insecurity, and nutritional habits and experience are greatly influenced by cultural values [111] such as fasting (no animal-source meals for the majority of months of the year) [112]. In contrast, the southern region of the country is known for highly-productive horticulture of fruits and vegetables in addition to other crops, which are easily accessible to the local community.
Trends in the nutritional status of adolescents over the study period showed no clear secular trends. This could happen for the fact that the reviewed studies covered quite a limited time period, and importantly were not truly longitudinal (they represent separate studies in different populations) and are therefore not ideal for a trend analysis. The prevalence of undernutrition and overnutrition has changed little, and both have coexisted in the community over the last decade. This could happen because, despite rapid economic growth and urbanization, wide wealth disparity persists in Ethiopia. The United Nations have adopted the first ever UN Decade of Action on Nutrition, from 2016-2025 to realize the goal set to eliminate all forms of malnutrition by 2030 [113]. To date, several of the nutrition targets which were agreed upon remain unmet and on the contrary, the double burden of malnutrition challenge is increasing. It is predicted that, if current trends continue, the absolute number of overweight people will have increased from almost 2 billion today, to 3.3 billion by 2030, equal to one third of the projected world population [114]. Nutrition interventions for the current generation of adolescents in Ethiopia would require context-and community-specific intervention approaches to address all forms of malnutrition.
Micronutrient deficiencies are also common in adolescents, with deficiencies of iron, zinc, iodine, folic acid, and vitamins A and B12 being the most common. Factors that could contribute are a lack of dietary diversity, a lack of fortified foods, food insecurity and low general knowledge and awareness about the need for micronutrients for health. While there was a steady reduction in iron deficiency anemia in girls between 2000 and 2016, there is an increase in boys over the same time period. This can be explained by the targeting of national initiatives selectively towards women of reproductive age over recent decades. Despite the high burden, there are no national or regional initiatives to tackle micronutrient deficiencies in the adolescent population at ground level.
Risk factors for undernutrition identified in this review include low socioeconomic status, maternal education and dietary diversity, food insecurity, higher family size, attending a public school, younger age, male sex and living in a rural setting. Risk factors for overnutrition included female sex, urban settings, lower levels of physical activity or more sedentary lifestyles, and coming from more wealthy families, having access to sweets/fast foods, older age and attending private schools. The sociodemographic and economic factors are modifiable causes of malnutrition, which could be addressed through effective context-relevant interventions, designed with the involvement of policy makers, experts, adolescents and their families.
The impact from the double burden of malnutrition could occur at the level of individual, household or nation. Individuals who were under-nourished as infants can have increased weight gain and obesity during adolescence or late in adulthood, while it is also possible for an obese person to have micronutrient deficiencies concomitantly. In the same household, some family members may be under-nourished while others are obese. The situation is the same for a given country.
Effective intervention strategies are required to tackle the double burden of malnutrition emerging in Ethiopia. The national strategy for adolescent and youth health and nutrition [115], produced by the ministry of health, recommends promoting participation and leadership by adolescents in the planning and implementations of adolescent-related nutrition programmes, implementing innovative health education and prevention programmes using the health extension programmes, schools, mass media and digital technologies. Specifically recommended interventions [115] include improving consumption of a balanced diet, with an emphasis on locally available and iron-rich foods, promoting healthy dietary habits, creating awareness of the intergenerational effects of malnutrition, creating community awareness on gender bias in household food distribution, targeted supplementation of iron and folic acid, the scaling up of facility-based nutrition assessment and counselling programs, advocacy and promotion of food fortification. These recommendations are in line with the WHO guide for implementation of effective action for improve adolescent nutrition [116]. These efforts will be more effective if global co-ordination, collaboration and integration can be achieved.
As adolescents are open for new ideas, and are concerned and interested about their health and life perspective, they could serve as the agents for change. Adolescence is therefore a window of opportunity for intervention [11,117]. Habits and experiences built during adolescence are more likely to last throughout life to some extent. Engaging adolescents in the design of their own nutrition and health interventions is likely to influence them positively. Involving young people as educators and intervention providers enables them to take responsibility for their nutritional health and is a way of allowing research to reach wider and hard-to-reach communities. A comprehensive intervention model that considers health, nutrition and wellbeing in general is more acceptable and impactful than targeting a single problem [116]. Such intervention models could combine counseling for nutrition and wellbeing, family life education, life skill trainings and positive behavior promotion (rather than focusing on discouraging negative behavior) to empower young people [118].

Strengths and limitations
Strengths of this review included a rigorous, standardised methodological approach and the involvement of multidisciplinary expertise through the TALENT collaboration. We have used definition of BMI for age z-score >1 for overweight and BMI for age z-score>2 for obesity in the meta-analysis for overnutrition. A limitation was that we were not able to use data for overweight when it was defined by weight for age z-score. Trend analysis overtime was not possible because of the limited range of years covered by the studies and the studies are mostly separate surveys in different populations rather than longitudinal data in the same population or setting.

Conclusions
While the magnitude of undernutrition remains high in Ethiopia, overnutrition is an emerging problem, leading to a double burden of malnutrition. Stunting and thinness are higher in boys and in rural settings while overweight and obesity are higher in girls and in urban settings. Half of adolescents found to have at least one micronutrient deficiency. There is a paucity of evidence from intervention studies to improve adolescent health and nutrition in Ethiopia. Therefore, appropriate and context-relevant intervention studies that address the various forms of malnutrition among adolescents should be designed and implemented, preferably with the active participation of adolescents themselves.